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Posts published by Kay E. Holekamp

Kay E. Holekamp, a zoologist at Michigan State University, writes from the Masai Mara National Reserve in Kenya, where she is studying the behavior of spotted hyenas.

Saturday, July 16

This week we witnessed a rare and fascinating sight: a pair of hyenas mating. Although I have been working with these animals in the wild for over 23 years, I have witnessed, on average, fewer than two matings per year. My research assistant, Tracy Montgomery, has been here watching hyenas several hours a day for 12 months now, and this was the first time she had ever observed a mating pair. Because so many readers responded to my “Male or Female?” blog post with questions about how in the world spotted hyenas have sex, I thought I should take advantage of this special occasion and tell you how it’s done. As you can imagine, given what you now know about hyena genitalia, mating is quite a challenge, especially for the male.

Though immigrant male hyenas are dominated by every other animal in the clan, even young cubs, they do almost all of the mating. The payoff for leaving the natal group and joining a new clan is that immigrants can take advantage of mating opportunities that are unavailable to males in their natal clans. Female spotted hyenas call all the shots when it comes to who will sire their cubs, and they rarely mate with adult natal males who are reproductively mature but have not yet dispersed. Considering the female’s social dominance over males and her bizarrely masculinized genitalia, sexual coercion is impossible in hyena society. If the female is not keen to mate with a particular male, then he’s just plain out of luck.

J. D’AmbrosiaThe three hyenas who originally discovered the dying buffalo approach it cautiously, eyeing its dangerous herd-mates.

Kay E. Holekamp, a zoologist at Michigan State University, writes from the Masai Mara National Reserve in Kenya, where she is studying the behavior of spotted hyenas.

Thursday, July 7

We had just started our afternoon “obs” a few days ago when we found three adult hyenas, all high-ranking females, sleeping on an open hillside. Then we saw something they hadn’t yet noticed: a very large male African cape buffalo that appeared to be dying. We could see from his worn teeth that he was very old, and though he could move his legs, he couldn’t seem to lift his head. One thing about studying large carnivores is that feeding can be difficult to watch. Although hyenas quickly kill smaller prey like gazelle by crushing the neck or skull, they tend to take down larger animals by disembowelment, letting their target bleed out, but that can take some time. We always hope the prey animal is in shock while this is happening, as there would be nothing we could do to speed up the prey animal’s death in any case. As the poet Tennyson put it, nature really is “red in tooth and claw.”

Eventually the three females got up from their nap and noticed the buffalo. They were silent as they approached it, avoiding its flailing limbs as they began to tear off pieces of flesh with their sharp teeth. When the dying animal bellowed in pain, its herd-mates rushed over and charged the hyenas, which scattered but then approached again to continue feeding. Still the hyenas were silent, suggesting either that they needed no help to subdue the prey or that they preferred not to share it with their clan mates. However, as often happens, other hyenas apparently heard the cries of the dying buffalo, and started appearing from all directions.

Kay E. HolekampA hyena leaving scent marks on stalks of grass. Like other mammalian carnivores, spotted hyenas inhabit a sensory world in which these chemical signals contain many types of information.

Kay E. Holekamp, a zoologist at Michigan State University, writes from the Masai Mara National Reserve in Kenya, where she is studying the behavior of spotted hyenas.

Monday, July 4

I had to laugh out loud this morning as I watched three of my students searching for hyena scent marks. They were wandering about, bent over at the waist, sniffing the tips of tall grass stalks at the far edge of the territory of our largest study clan. They inched slowly through the tall grass, moving their noses ever so carefully up and down one stalk of grass after another. My students were engaged in an olfactory treasure hunt in which they looked like demented entomologists searching for new life forms. In a way, that is exactly what they were doing.

Kay E. HolekampStudents searching for hyena paste.

One of the projects we are working on in the Masai Mara National Reserve now addresses the question of whether microbial organisms interact symbiotically with hyenas to influence the chemical messages the hyenas send to one another. Like many other carnivores, including domestic dogs and cats, spotted hyenas have scent glands above the anus on both sides of the body, and these glands in adult hyenas produce a yellowish waxy secretion known as “paste.” The paste accumulates in small anal “pouches” adjacent to the glands themselves. When we immobilize adult hyenas, we routinely collect paste from their anal pouches by scooping it out with a sterile spatula, and then we freeze it for later analysis. However, when the adult hyenas are awake, they deposit scent by squatting, lifting the tail and rubbing their anal pouches over grass stalks, which leaves smears of their paste on the plants. Although I find that a spatula full of paste has a strong musky odor, I can rarely see or smell paste deposits on grass stalks. The students out here vary in their ability to detect the odor of paste on grass stalks; some of them are as bad at this as I am, but others can accurately pick out a grass stalk marked by a hyena from among hundreds of unmarked stalks.Read more…

Kay E. Holekamp, a zoologist at Michigan State University, writes from the Masai Mara National Reserve in Kenya, where she is studying the behavior of spotted hyenas.

Monday, June 27

One very hot topic at breakfast and dinner in camp this week has been what to name Roosevelt’s new cub. Roosevelt is a young adult female who recently gave birth to her first litter. Although the mean litter size is two among spotted hyenas, first-time mothers often produce only one cub, and that’s what happened in Roosevelt’s case. George Schaller, the famous Bronx Zoo biologist who conducted wonderful long-term field studies of lions, gorillas and snow leopards, exhorted all field biologists to be very thoughtful in naming their animals. My students are not merely thoughtful in selecting hyena names, they are completely obsessed.

If you are going to engage in long-term study of long-lived and highly social mammals, it’s important to be able to keep track of large numbers of individuals at once, and it is also often helpful to be aware of who is related to whom while the animals are interacting with one another. In our work we use naming conventions to help even inexperienced observers keep track of our hyenas and the relationships among them. Each adult male who immigrates into one of our study clans is assigned the name of a city. Current immigrant males in our largest study clan include Dublin, Lansing, Chicopee, Kyoto, Juba and Harlem, among others. Naming of immigrants is not terribly controversial. Naming of new cubs, on the other hand, can make camp feel like a war zone.

Kay E. Holekamp, a zoologist at Michigan State University, writes from the Masai Mara National Reserve in Kenya, where she is studying the behavior of spotted hyenas.

Monday, June 27

A couple of days ago my students and I darted a young adult hyena named Dionysus. This is a particularly interesting animal, as it is the youngest adult offspring of our last alpha female, Murphy, who was killed by lions in April. Murphy’s youngest adult male offspring will almost certainly disperse voluntarily to a new clan within the next year or two, but her youngest adult daughter should remain throughout her life in her natal social group, called a “clan,” and take over there as the alpha female. In the latter case, assuming this animal is able to fend off attacks from its very brawny older sisters, Juno and Loki, Dionysus will rank first in a clan of more than 90 hyenas! If Dionysus ranked first, she would be able to usurp food from any other hyena in the clan, live a long life and produce more surviving offspring than any other female.

H. E. WattsTwo young spotted hyenas engage in a greeting ceremony.

Although spotted hyenas are notoriously difficult to sex, my students and I are typically very good at determining the sex of hyenas using a variety of subtle morphological cues as they move around or engage in “greeting ceremonies” with one another. However, every once in a while a hyena fools us, and an individual believed to be a male for two or three years one day shows up nursing cubs at the den! None of us had ever been able to sex Dionysus with complete certainty, even though this animal will be 2 years old in a few weeks. We had all thus been looking forward to darting Dionysus because we expected this animal would be easy to sex once we could examine it very closely. However, this time, even after the animal fell asleep and we rolled it over so we could examine its genitalia, we continued to get mixed messages.

Kay E. HoleKamp, a zoologist at Michigan State University, writes from the Masai Mara National Reserve in Kenya, where she is studying the behavior of spotted hyenas.

Tuesday, June 21

“When there are so many nicer animals out there, why study hyenas?”

That is the question my mother asked me when I first told her back in the mid-1980s that I was planning to move to Kenya to study spotted hyenas. Back then, before I actually started working with hyenas, I would have answered by saying, “Because I have an opportunity to go to Africa to study an interesting large mammal, and those kinds of opportunities are too rare to pass up. I’ve wanted to do something like this all my life, and now I have a chance to do it.”

Back in those days, I thought I would move to Kenya for a few years, conduct a dissertation-length project on spotted hyenas, then move on to a study yet another new animal in another new place. I had no idea then that I would just fall in love with these animals, or that they would hook me so completely with their complexity and their oddity. Nor did I have any idea back then how useful a model system these hyenas might offer for studying phenomena as wide-ranging as immune function, skull morphology, social networks, conservation biology and the evolution of intelligence.

If my mother asked that same question today, I’d answer it very differently.

Kay E. HolekampHyenas in the Masai Mara National Reserve in southwest Kenya.

Kay E. HoleKamp, a zoologist at Michigan State University, writes from the Masai Mara National Reserve in Kenya, where she is studying the behavior of spotted hyenas.

Thursday, June 16

After nine months trapped behind my desk in Michigan, I’m finally back in the African bush, the one place I love above all others on earth. Only here are the skies so vast you can see both rainbows and bright sunshine while sitting under a drenching downpour from a massive black thunderhead. Only here can you be sure to see some weird and interesting form of animal life no matter where you look. Ever heard of a duiker? A solifugid? A pangolin? A springhare? A camaroptera? They all live here, along with hundreds of other animal species. Elephants forage in the riverbed that runs beside our camp, hippos chuckle in the pool below my tent, the shrill calls of white-browed robin-chats tell me when I have overslept, baboons steal our sugar jar whenever one of us is dumb enough to leave it unattended, and giraffes browse silently through camp after dark like great ships drifting in the night.

But the best thing about the African bush is that it is where you can find spotted hyenas.

As I have done every spring since I joined the faculty in the department of zoology at Michigan State University, I’ve once again traded sitting through endless committee meetings and grading overwhelming stacks of student papers for life in a tented camp where my most pressing concern every day is whether or not I will encounter a grumpy hippo on the footpath connecting my sleeping tent to our lab tent and dining area.